Note 14 - Stock Based Compensation - Stock-based Compensation Expense (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Stock-based compensation expense $ 4,609 $ 4,424
Cost of Sales [Member]    
Stock-based compensation expense 92 123
Research and Development Expense [Member]    
Stock-based compensation expense 813 764
Selling, General and Administrative Expenses [Member]    
Stock-based compensation expense $ 3,704 $ 3,537